The present invention concerns an assembly system and a method employing this system, as well as devices, particularly container devices such as boxes or cases, provided with this system.
Hereinafter various definitions of the concepts employed are given as follows;
By displacement there is meant any translation, rotation and combinations of translations and rotations.
By interface zone there is meant any junction or joint plane between two parts of an opening/closing system or assembly.
By sliding zone there is meant any zone of the approach of one part of an assembly system onto the other part of this system.
In relation to retention force, the expression normal force will be used in the case of a translation, and the expression axial force in the case of a rotation.
In relation to clamping force, the expression force perpendicular to the displacement will be used in the case of a translation, and the expression radial force in the case of a rotation.
By thin wall there is meant any wall made from plastic or metallic materials; in foils, formed notably by thermo forming, stamping or any other equivalent technique, and shaped by rotary moulding, injection moulding, blow moulding etc.
In many fields, such as those of cosmetics, perfumery, foodstuffs and consumer goods, products or articles are sold in rigid boxes or cases. These boxes or cases generally comprise a main part destined to contain the product or the article, and a removable part, for example a lid or closure, with which there is associated an assembly system.
Reversible assembly systems are known, for example, that operate by screwing, by clipping, by forcible insertion or yet again by hinging. Existing assembly systems, however, display inconveniences in use, being in particular difficult and even tricky to manipulate when it is necessary to effect several turns of the screw, or yet again being fragile when they are subjected to repeated use as can be the case with compact discs cases or with powder compacts in perfumery. Existing assembly systems are costly to manufacture. They require different male and female parts involving very costly equipment for their manufacture with a production-rate held back by the internal kinematics.
Tubular assembly systems are known, particularly from Publication WO94/07038, that employ the effect of clamping by radial jamming produced by rotation of a male tubular part within a female tubular part, these tubular parts having appropriate shapes for example, in the form of cams. In these tubular assembly systems the problems of gripping and of ergonomics do not arise.
It is not, however, the same in the majority of the previously-mentioned applications, with which the consumers want boxes or cases allowing easier and more rapid access to the products or articles contained in these boxes or cases.
The object of the present invention is to satisfy these desires on the, part of the consumers as well as on the part of the manufacturer and to remedy the previously mentioned inconveniences by proposing a rapid assembly system which is allied with a much greater facility in use and a greater solidity as well as requiring simple equipment, enabling increased rates of production without need of internal kinematics.
The assembly system according to the invention preferably, but non-limitingly, envisages devices provided with thin walls. It is particularly appropriate for assembly systems to be made from easily or strongly deformable materials. This relates notably to specific technical applications and sectors for example in the foodstuffs or cosmetic industry, which demand a resistance to removal (axial retention or normal to the interface zone) as well as a sealing of the container or the packaging equipped with this system. Besides that, for these products one generally looks for recloseability guaranteeing preservation and hygiene, most especially when it relates to products not consumed all at once, in foodstuffs or pharmacology. More generally, the problem of normal or axial retention arises when the contents exert a pressure within the enclosure (gaseous drinks, spray, etc . . . ) or when one wants the assembly to he able to he lifted by the lid.
It is to be noted that the system according to the invention moreover allows for a greater margin of tolerance than with previous methods, and thus yields a supplementary advantage in terms of the life-expectancy of the equipment, backlash elimination, and assemblies of different materials displaying distinct manufacturing tolerances, for example in plastic/glass, plastic/wood assemblies.
In the case of rotation, the action is compensated by reactions which have radial components but also axial components. The axial retention is obtained due to the clamping force thanks to a deformation of the material. The judiciously exploited deformations enable creation of an undercut in use although this undercut does not exist during manufacture. This enables one to obtain a retention approaching that of a nut-and-bolt, quarter turn or swallow tail system, while retaining the advantages and the originality of a system based upon manufacture without undercut, therefore easier, less costly and more rapid.
As for sealing, the invention makes it possible to impose a lid onto a base so as to ensure horizontal sealing directly or perhaps achieved via an intermediate jointure, squeezed between the lid and the base. In the rest of the description, the terms lid and base must he understood in a broad sense.
One can advantageously envisage a mode of embodiment in which a slope is imparted in the plane normal to the interface zone and substantially tangential to the displacement. In the case of a rotation, it mimics the effect of a screw thread. In this way, after being clamped, the lid tends to be attached to the base, with a retention and a clamping of the lid of radial type but also axially.
Thus, due to the absence of undercut, one secures minimization of tooling costs and improvement in production rates.
The assembly system according to the invention can be applied to any radius of curvature and specifically in translation with an infinite radius of curvature, as well as to complex curves.
So far as concerns the deformation of the materials employed in the assembly system according to this second version of the invention, one either can reckon to remain within the elastic limit of the materials or not, implicating a remanent deformation or not. The re-use of the assembly can influence the remanent initial deformation or not.
One can also envisage a device consisting of a stack of several pieces of different sizes and shapes, provided with assembly systems according to the invention, in order to achieve volume modularity.
Furthermore, several assembly sub-systems can be distributed at several points on a device provided with a system according to the invention.
Thus, the assembly system according to the invention secures better ergonomy of use than the previous systems of assembly. In fact, the handling of the assembly or disassembly effected, by an user is aided by spatial guidance of the two parts of the system.
According to this other aspect of the invention particularly appropriate when scarcely-deformable materials are employed for making the parts of the assembly, the first and second coupling means each comprises one or more ramps disposed circularly on one internal face of the corresponding first or second part, and the ramps of the first coupling means cooperate with the ramps of the second coupling means so as, by an external act of rotation of one part relative to the other part achieved in a fraction of a turn, either to get a helicoidal motion of the part relative to the other part so as to close said assembly by and reach a progressive radial jamming, or get a reverse helicoidal motion so as to separate and decouple the parts.
Thus, the operations of assembly can be achieved without the exterior of the part including any protruding or directly grippable portions. The opening action takes place by the combination of pressing and rotating one part relative to the other. In fact, on exerting a rotation of one part, the other tends to displace following a translation motion, which has the effect of separating the two parts thus permitting them to dissociate or de-couple from gripping one of them.
The lower part and the upper part can be identical as regards the nature of the ramps, ideally the first and second coupling means can be hermaphrodites, which notably has the major advantage of requiring only one pressing for manufacture of the two parts for example by plastic injection moulding.
The jamming of the coupling means is achieved by providing projecting parts and hollow parts on the ramps, the projecting parts of the ramps on one part accommodating themselves in the hollow parts of the ramps of the other part. The size of the hollow parts diminishing progressively as the operator effects a rotation in the clockwise sense, this results in a jamming of the parts as they emerge from within the hollow parts. The clearance, positive at the start, becomes progressively negative. The two assembled parts can withstand an attempt at opening normal to their plane of assembly to a greater extent than these two parts will have been jammed one against the other by an attempt brought about by rotation in the clockwise sense.
In relation to data carrying discs, from W09414160 there is known a case comprising two flaps articulable around a hinge axis, in which the disc is held by the center via a retainer piece making spring fixture with one of the flaps.
It is often the case that the elements of the case constituting the pivotal interconnection and the fixture of the disc in position become fragile, deteriorate and break, particularly as a result of impacts.
To overcome these inconveniences, within the scope of the present invention there is proposed a case for compact discs provided with an assembly system according to the invention arranged centrally thereof.
Besides that, one can advantageously envisage that at least one of the two removable parts shall be designed to induce an optical magnification of data and/or of artwork disposed on at least one of the faces of the disc or of a booklet contained in this case.
Between the two removable parts of the case one can insert a support jacket or a booklet of greater dimensions than those of the said case which is subsequently enclosed in a plastic film.
According to yet another aspect of the invention, there is proposed a frame for accommodating a case according to the invention. The external dimensions of this frame can moreover correspond to those of a standard compact disc case, thereby enabling use of existing storage and distribution racks one can equally envisage the manufacture of this frame in conjunction with one of the parts of the case. The frame can for example be in the shape of an eye and be designed in a second version to provide vertical hold in a stable and properly-placed position so as to enable consultation.
According to another aspect of the invention, there is proposed a method of assembly embodied in a system according to this second version of the invention fitted with a device in two removable parts, including the following steps;
bringing the two removable parts of the device provided with this system into contact, these removable parts comprising complementary forms of coupling,
displacing one part relative to the other along a sliding zone,
assembly by progressive clamping up to deformation of the surface substantially normal to the zone of the interface.